Generic safety switches for safety appliances to be monitored, such as ones on production equipment, are disclosed in DE 43 28 296 C1.
Conventional safety switches have a housing in which a switching disk is rotatably mounted around a shaft and into which an actuator for initiating the switching process may be introduced, and have a locking mechanism for blocking the switching disk, as disclosed in EP 0 778 595 A1 (corresponding to U.S. Pat. No. 5,898,143). The locking mechanism has, in the safety switch illustrated in this patent, a locking element which may be moved against the force of an energy accumulator. In a position blocking the switching disk, the locking element may be moved into engagement with a groove on the circumferential surface of the switching disk. The locking element is contained in the housing in the process. Engagement with the switching disk takes place in a radial direction relative to the axis of rotation. In the event the application of a strong force, the danger exists that the circumferential surface of the switching disk may be damaged by the locking element.
JP 8-203 389 A discloses a safety switch in which a locking element pivotably mounted in the housing is engaged in a groove in the switching disk in the radial direction. This engagement blocks the rotary movement of the switching disk.
JP 7-260 089 A discloses a safety switch in which an elongated locking rod may be moved radially relative to the axis of rotation of the switching disk. The rotary movement of the switching disk is released when the actuator is introduced.
DE 43 38 910 C1 discloses a safety switch in which an integral release and locking element may be moved radially relative to the switching disk when the actuator is introduced. Radial movement frees the rotary movement of the switching disk.
DE 36 09 043 C2 discloses a safety switch having a switching disc rotatable in a housing, an actuator inserted in the housing to initiate the switching, and a locking mechanism. Such safety switch has a locking element contained in the switching disk and acting against the action of an energy accumulator. The locking element is engaged in an associated recess in the housing in a position blocking the switching disk. Disadvantageously, the locking element is moved directly by the actuator to be introduced, diminishing the reliability of handling.